Engine - Shudder or Chuggle at Slow Speeds in High Gear

90pontiac21
Bulletin Number: 90-6-46
Reference Number: 036518R
Publish Date: 11/90
Subject: ENGINE CHUGGLE AT LOW SPEEDS (NEW PROM PACKAGE TO RAISE TCC LOCKUP SPEED)

Models

Affected: 1990 GRAND AM MODELS W/2.5L AND 3T40 AUTO TRANSMISSIONS

Condition: Some owners of 1990 Grand Am models with 2.5L engines may comment about an engine shudder or chuggle condition when driving at slow speeds in high gear.

Cause: Converter clutch lockup at slow speeds during some driving conditions.

Correction: A new PROM package has been released which raises the TCC lockup speed to the following:

1990 Grand Am With 2.5L Engine (FROM 29 TO 43 MPH)

Usage PROM Pkg. P/N Broadcast Code Scanner I. D.

All 16159793 AXCM 9801

Parts are expected to be available on November 26, 1990. Until then, normal part orders will not be accepted by GMSPO. Only verifiable emergency VIP orders will be accepted. SPO will make every effort to obtain parts. All parts will be placed on 400 control to waive VIP surcharges. However, the part will be shipped premium transportation at dealer's expense. All other order types will be cancelled as incorrectly ordered while the 400 control is in place.

Labor Operation Number: T0500
Labor Time : .3 Hours